Baudouin Nicks

Airborne dust and aeroallergen concentrations in different sources of feed and bedding for horses

Standardized methods were used to make quantitative and qualitative assessments of respirable dust and aeroallergens in feed and bedding for horses. Concentrations of airborne dust were measured by using a Rion particle counter, and levels of major aeroallergens implicated in chronic obstructive pulmonary disease were measured by using an Andersen sampler. Laboratory conditions allowed comparison of the different sources of forage, supplements, and bedding without external influences such as ventilation, external temperature and horse activity affecting the result. Grass silages of approximately 50% dry matter and alfalfa pellets appeared to be very good sources of forage with low levels of dust and aeroallergens. The studied good quality straw was significantly less dusty with fewer allergens than the wood shavings. Supplements, such as whole grains and molassed concentrates, contained many respirable particles and aeroallergens. Rolled grains were significantly more dusty than good hay.

Gaseous emissions during the fattening of pigs kept either on fully slatted floors or on straw flow.

The aim of this study was to compare the environmental impact of the straw-flow system for fattening pigs with the slatted-floor system by measuring pollutant gas emissions such as ammonia (NH3), nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2), manure nitrogen (N) content and emissions of water vapour (H2O). Three successive batches of 32 pigs were fattened. For each batch, pigs were allotted to two groups raised in separated rooms fitted either with a concrete totally slatted-floor system (0.75 m2 per pig) or with a straw-flow system (0.79 m2 per pig). With this last system, pigs were kept on a sloped floor, straw being provided daily at the top of the pen. Throughout the fattening period, about 34.4 kg of straw were supplied per pig. The straw, mixed with dung, travelled down the slope by pig motion and went out of the pen to a scraped passage. The solid fraction was scraped every day, stored in a heap in the room and removed every month, 1 week before each period of gaseous emission measurement. The liquid fraction was automatically pumped from the scraped passage into a hermetic tank, which was emptied at the end of each fattening period. Rooms were ventilated mechanically in order to maintain a constant ambient temperature. Once a month, the emissions of NH3, N2O, CH4, CO2 and H2O were measured hourly for 6 consecutive days via infrared photoacoustic detection. Mean daily emissions per pig fattened on the slatted floor or on the sloped floor were, respectively, 4.98 and 13.31 g NH3, 0.67 and 0.68 g N2O, 15.2 and 8.88 g CH4, 548 g and 406 g CO2 equivalents, 1.61 and 1.77 kg CO2 and 2.33 and 2.95 kg H2O. Except for N2O emissions, all the differences were statistically significant (P < 0.001). From the slatted-floor system, the amount of slurry removed per fattening period was on average 256 kg per pig. From the straw-flow system, solid manure amounted on average to 209 kg per pig and liquid manure to 53 kg per pig. The total N-content of the manure was 2.23 kg N per pig with the straw-flow system (solid and liquid manure) v. 3.26 kg N per pig for slurry from the slatted-floor system. This reduction of 30% observed with the sloped floor was mainly explained by the higher level of NH3-N emissions.

Use of a shelter by grazing fattening bulls: effect of climatic factors.

The time spent under a shelter by eight grazing fattening bulls of the Belgian Blue breed in each of 3 years consecutively for a total of 48 days was recorded using a time-lapse recorder with infrared illumination. During one grazing period, data were collected over 35 days (experiment 1). Observations were divided into 166 h with rain (20%) and 674 h without precipitation (80%). The average occupation rates were 15·4 (s.e. 29·1) % for the hours with rain and 4·5 (s.e. 14·8) % for the hours without precipitation ( P 2 or from 2 h. Experiment 2 (13 days of observation) examined the influence of temperature and solar radiation on the use of shelter. The occupation rates were 21 (s.e. 23) % during the daylight hours (07.00 to 19.00 h), 6 (s.e. 8) % during the night (19.00 to 07.00 h) and 14 (s.e. 14) % during a 24-h period. The occupation rate between 07.00 and 19.00 h was significantly correlated to the mean daily temperature (r = 0·75), the maximum daily temperature (r — 0·86) and the direct solar radiation time (r 0·60). When the maximum daily temperature exceeded 20°C, the use of the shelter increased from 10 to 49% of the daylight hours. There was no significant difference between the live-weight gains of animals from the observed group and those of other bulls on an adjacent pasture without shelter. Nevertheless, these observations suggest that a shelter may improve the welfare of grazing cattle.

Resting behaviour of Friesian bulls maintained in a tie-stall barn under two patterns of lighting

Abstract Standing and lying bouts of 6 Friesian bulls were continuously recorded during two 1-week trials under two patterns of lighting. In the first trial the stable was lit from 06.00 to 18.00 h, and it was continuously lit in the second trial. The bulls averaged 154.2±17.6 kg at the start of the experiment. Bulls were tied up in a stanchion barn. The front part of the stall floor was covered by a rubber mat (0.9 m long). The back part was a metal grid. Standing up and lying down were recorded by an electrical device. A potentiometer was mounted 2.5 m above each animal. The cursor of the potentiometer could be moved by an elastic band tied at animal rump level to a strap placed around the body of the animal. When the animal did not lie down the elastic band was unstretched and the electrical resistance was nil. When the animal rested, the tension of the elastic band drew the cursor down; in such a position, the resistance was higher than 200 ohms. Each change in position, the time and the number of the animal were recorded on a cassette tape by a datalogger. From 18.00 to 06.00 h (night), the mean standing time was 1.11 h in the first trial and 1.61 h in the second. From 06.00 to 18.00 h (day), the corresponding values were 6.37 and 5.20 h, respectively. Differences between day and night and between trials were significant. The mean numbers of standing bouts per 24 h were 12.18 and 12.45, respectively, for both trials. About half of the standing bouts (44.4% in Trial 1, 49.5% in Trial 2) were 1 h were 18.9 and 16.4% of the whole. Differences between trials were not significant. The percentage of standing bouts of short duration ( In the first trial, the proportions of lying bouts of 1 h were 7.3 and 58.7%. In the second trial, the corresponding values were 4.0 and 60.3%. Differences between trials were not significant. On average, animals rested 68.8 and 71.6% of the time for 50:50 and continuous lighting, respectively. The percentage of lying bouts > 1 h was significantly higher during the night than during the day (71.7 vs. 29.5% in Trial 1; 70.3 vs. 34.6% in Trial 2).

Effects of available surface on gaseous emissions from group-housed gestating sows kept on deep litter

In the European Union, the group-housed pregnant sows have to have a minimal legal available area of 2.25 m2/sow. However, it has been observed that an increased space allowance reduces agonistic behaviour and consecutive wounds and thus induces better welfare conditions. But, what about the environmental impacts of this greater available area? Therefore, the aim of this study was to quantify pollutant gases emissions (nitrous oxide, N2O, methane, CH4, carbon dioxide, CO2 and ammonia, NH3), according to the space allowance in the raising of gestating sows group-housed on a straw-based deep litter. Four successive batches of 10 gestating sows were each divided into two homogeneous groups and randomly allocated to a treatment: 2.5 v. 3.0 m2/sow. The groups were separately kept in two identical rooms. A restricted conventional cereals based diet was provided once a day in individual feeding stalls available only during the feeding time. Rooms were automatically ventilated. The gas emissions were measured by infra red photoacoustic detection during six consecutive days at the 6th, 9th and 12th weeks of gestation. Sows performance (body weight gain, backfat thickness, number and weight of piglets) was not significantly different according to the space allowance. In the room with 3.0 m2/sow and compared with the room with 2.5 m2/sow, gaseous emissions were significantly greater for NH3 (6.29 v. 5.37 g NH3-N/day per sow; P < 0.01) and significantly lower for N2O (1.78 v. 2.48 g N2O-N/day per sow; P < 0.01), CH4 (10.15 v. 15.21 g/day per sow; P < 0.001), CO2 equivalents (1.11 v. 1.55 kg/day per sow; P < 0.001), CO2 (2.12 v. 2.41 kg/day per sow; P < 0.001) and H2O (3.10 v. 3.68 kg/day per sow; P < 0.001). In conclusion, an increase of the available area for group-housed gestating sow kept on straw-based deep litter seems to be ambiguous on an environmental impacts point of view. Compared with a conventional and legal available area, it favoured NH3 emissions, probably due to an increased emitting surface. However, about greenhouse gases, it decreased N2O, CH4 and CO2 emissions, probably due to reduced anaerobic conditions required for their synthesis, and led to a reduction of CO2 equivalents emissions.

Comparison of feeding behaviour and performance of weaned piglets fed with two types of dry feeders with integrated Drinkers

Performance of 80 (tests 1 and 2) or 60 (tests 3 and 4) weaned pigs were compared when using ‘Tubetype’ feeder (T), allowing the animals to mix meal and drinking water, or another type (V) where drinking and eating places are separated. The difference in growth rate was not significant but the mean daily water consumption (1 per pig per day) was higher with T than with V in each test but significantly only in tests 1 and 3 (1·84 v . 1·40, and 2·11 v . 1·26, P Feeding behaviour was assessed during tests 2 and 4. Multifactor analysis of variance revealed effects ( P v . 21·5 per 24 h and 4·5 v . 3·7, P P P

Comparison of performance, water intake and feeding behaviour of weaned pigs given either pellets or meal

Performance, water intake and feeding behaviour of two groups of 30 (trial 1), 40 (trial 2) or 50 (trial 3) weaned pigs offered either pellets or meal of the same formulation were compared. Average daily weight gains (ADG) were higher for pigs given pellets rather than meal in trials 2 (413 v. 363 g/day, P The occupation time (ОT) and the number of animals using the feeder simultaneously (N) were higher when pigs were given meal rather than pellets, whatever the animal density: trial 1: 82·6 v. 69·9% (P = 0·05) and 3·8 v. 2·3 (P 0·05) and 5·2 v. 3·1 (P The greater the group size, the lower were ADG (both diets) and DWI (only with meal) and the higher were ОT and N (both diets). Furthermore, significant linear and curvilinear regressions of DWI, ОT and N according to time were calculated. In conclusion, pigs need more time to eat meal than to eat pellets. Thus the number of pigs per feeder has to be adapted to the food presentation. Too high a number of pigs per feeder impairs feeding behaviour and eventually welfare, by preventing preferential diurnal feeding activity and this may affect productivity.

In vitro short-term study of ammonium-nitrogen production from cattle urine : influence of ampicillin, hydroquinone and animal litter materials

The production of NH + 4 -N following in vitro incubation of cattle urine was monitored for 24 h in the presence of ampicillin sodium salt (0, 32, 64, 128 mg/l), hydroquinone (0, 16·7, 33·4, 66·8 mg/l), wheat straw (0, 3·3, 6·6, 13·2 g/l) or spruce sawdust (0, 3·3, 6·6, 13·2 g/l) with (20 IU) or without urease. Each concentration of ampicillin, hydroquinone, wheat straw or spruce sawdust was tested in triplicate. The equipment consisted of Woulff flasks containing 300 ml of a buffered solution (0·02 M ; pH 7·50) with 1 ml of cattle urine. The cattle urine was characterized by measuring the main nitrogen contents, which were 6·52 mg total-N/ml, 5·96 mg urea-N/ml and 0·026 mg ammonium-N/ml. The initial pH of urine was 7·84. Ammonium and nitrate concentrations, and pH were monitored at zero- time and after 3, 6 and 24 h of incubation with the cattle urine. The addition of urease to the flasks containing urine induced a significant increase in the production of ammonium-N, from 1·83 to 6·32 mg NH + 4 -N/flask after 24 h of incubation. In the presence of urease, an inhibitory effect was recorded in NH + 4 -N production with ampicillin and spruce sawdust. In contrast, hydroquinone inhibited urease activity and wheat straw adsorbed the NH + 4 -N produced, both causing a dose-dependent relationship. In the absence of urease, ampicillin, hydroquinone, wheat straw or spruce sawdust caused a dose- related decrease in NH + 4 -N production. However, the highest amounts of wheat straw (6·6 and 13·2 g/flask) exhibited a temporary increase in NH + 4 -N production during the first 6 h. This is probably due to a generation of extra NH + 4 -N as compared to the control flasks without straw. However, at 24 h, the situation paralleled the other materials. Although pH increased approximately from 7·50 to 7·65 during the hydrolysis of urea in the presence of urease, no gaseous ammonia was volatilized into a 0·1 M HCl flask. Moreover, no increase in nitrate concentration was found during the incubation. The present results suggest that ampicillin, hydroquinone and spruce sawdust could be used in order to reduce NH + 4 -N production from cattle urine. The NH + 4 -N already produced could probably be absorbed on wheat straw.

Influence of Supplemental Lighting on the Resting Behaviour of Fattening Bulls Kept in a Stanchion Barn

The resting behaviour of 12 fattening bulls was observed under three patterns of lighting: natural daylength, natural lighting during the day and 4 h supplemental lighting after sunset (from 18.00 to 22.00 h), natural lighting during the day and 4 h supplemental lighting before sunrise (from 03.00 to 07.00 h). The standing and lying bouts were recorded continuously during 1 week in each trial by an electrical device. Bulls were ∼ 18 months old and their average weight was 421.6±26.4 kg. They were tied up in a stanchion barn. The time spent standing from 18.00 to 22.00 h and from 03.00 to 07.00 h increased by 42% (1.48 vs. 1.04 h) and by 87% (1.01 vs. 0.54 h), respectively, when light was provided (P 15 min was 53% in darkness and 74% with artificial light. From 03.00 to 07.00 h, the corresponding values were 17 and 56%. During the period of darkness common to the three trials (from 22.00 to 03.00 h), the percentage of time spent standing was on average 20%. There was no difference between trials. During the natural daylight period, the corresponding values were 44, 36 and 45%, respectively, in the three trials (P<0.05). The differences during this period might be due to the external stimuli which could have varied to a larger extent between trials during the day than during the night. Although there was a highly significant effect of light during the periods of artificial lighting, no significant effect was observed on a 24-h basis. Bulls were standing, on average, 31% of the time.

Resting behaviour of Belgian White-Blue and Friesian fattening bulls in a tie-stall barn

Abstract Standing and lying bouts of 11 fattening bulls were recorded continuously during two 1-week trials. There were 6 Friesian bulls and 5 double-muscled bulls from the Belgian White-Blue breed. At the start of Trial 1, the Friesian and Belgian White-Blue bulls averaged respectively. Trial 2 started 84 days later when the liveweight was about 100 kg more. The bulls were tied up in a stanchion barn. Standing up and lying down were recorded by an electrical device. The mean lying times per 24 h of the Friesian bulls were 16.52 h in Trial 1 and 16.13 h in Trial 2; the corresponding values for the Belgian White-Blue bulls were 15.77 and 16.82 h. Differences between breeds and between trials were not significant. The variability between the Belgian White-Blue bulls was larger than between the Friesians. The mean number of lying bouts per 24 h ranged from 12.31 to 16.97, the highest value being observed with the double-muscled animals in Trial 2. Resting behaviour was different between the day and the night. From 18.00 to 06.00 h, the lying time ranged from 9.75 to 10.89 h according to group; from 06.00 to 18.00 h, the corresponding values were 5.56 and 6.71 h. The repartition of lying bouts according to their length was not different between trials for the Friesian bulls. The proportions of lying bouts shorter than 15 min and longer than 1 h were on average 7.6 and 59.2%. For the Belgian White-Blue bulls, the repartition was different between trials: the proportions of lying bouts shorter than 15 min were 4.6 and 7.9% in Trials 1 and 2, respectively; those longer than 1 h were 60.6 and 43.6%. The proportions of lying times of long duration (>2 h) and standing times of short duration (